Pelican by default creates a separate page for each category. Themes list all the articles filed in that category at its page. Elegant takes a different approach which is, “all Categories but with zero clutter”.
It lists all the categories and their articles on the same page. To reduce clutter and utilize space efficiently, each category and its list of articles is enclosed in collapsible accordions.
Here is how categories appear collapsed
And this is how they appear uncollapsed
Did you notice that categories are listed in ascending alphabetical order and articles are sorted by their date in descending order?